Coordination And Control Flashcards
What happens at a synapse?
- The inpulse reaches the synaptic bulb (the end of the neurone)
- Vesicles containing the transmitter move towards the cell membrane at the synapse
- Vesticles release their neurotransmitter into the gap between the 2 cells
- Neurotransmitter diffuses across the gap
- The Neurotransmitter reaches the membrane of the next cell
- When enough neurotransmitter reaches the next cell an impulse will occur
- The impulse travels along the next cell
- The used neurotransmitter is broken down by an enzyme
List the structures of the eye (use a diagram)
Eyelid Ciliary muscle Cornea Iris Aqueous humer Pupil Lens Suspensory ligament Conjunctiva Eyelash Sclera Vitreous humer Retina Fovea Optic nerve “Blind spot”
What is a stimulus?
Any change in the environment around us
What are the 3 main components of the animal nervous system?
Receptors
Coordinator
Effector
What is a receptor?
Receives/detects the stimulus (e.g. temperature sensors on the skin)
What is a coordinator?
Determines the response (e.g. the brain and spinal cord)
What is an effector?
Carries out the response (e.g. biceps muscle)
What is the sequence of a response?
Stimulus -> receptor -> coordinator -> effector -> response
What is the function of the iris?
Controls how much light enters the eye
What is the function of the pupil?
Space in the iris through which light passes
What is the function of the cornea
Transparent front part of the eye that causes some bending (refraction) of light
What is the function of the Conjunctiva?
Thin transparent protective outer covering that helps prevent the entry of microorganisms
What is the function of the retina?
Receptor of light.
Layers of light sensitive cells that can sense different coloured light (cone cells) as wel as cells that dont sense colour at all (rods)
What is the function of the Lens
Refracts light to obtain a focused image
What is the function of the optic nerve?
A bundle of nerves that carries impulses from the retina to the brain.
What happens to the eye when focusing on a distant object?
Ciliary muscles relax
Suspenspry ligaments pulled tight
Lens pulled thin
Light rays arrive parallel; cornea refracts rays; lens is thin as little additional refracting is necessary to focus light on the retina.
What happens to the eye when focusing on a nearby object?
Ciliary muscles contract
Suspensory ligaments slackened
Lens allowed to bulge
Light rays diverge; cornea refracts rays; lens is thicker as additional refraction is necessary to focus light on retina
List some adaptations of the neuron
Long length
Insulating sheath
Branching ends
List the parts of a neuron (use a diagram)
Dendrite Cell body Nucleus Axon Myelin sheath Schwann cell Node of ranvier